氧化锌避雷器测试仪校准探讨

本文介绍了氧化锌避雷器测试仪电压和全电流测量误差的校准方法、接线示意图.     

氧化锌避雷器带电测试仪校验方法探讨

描述了传统阻容网络校验氧化锌带电避雷器测试仪的误差,介绍了新型智能化氧化锌带电避雷器测试仪校验装置的原理和结构,经国家高电压计量校准合格后,用于对各种类型的氧化锌避雷器带电测量仪进行校验.该装置采用标准源方式、数字化电路和全电脑控制,实验表明,该设备使用方便,具有0.5级的高精度,有着广泛的应用前景.     

金属氧化锌避雷器的现场试验

金属氧化锌避雷器的现场试验于逢林（浙江省工业设备安装公司杭州３１００１６）金属氧化锌避雷器是目前较先进的过电压保护电器。其核心元件电阻片采用氧化锌配方制作，改善了电阻片非线性伏安特性，提高了过电压通流能力。金属氧化锌避雷器以结构特征可分为无间隙和有串...     

氧化锌避雷器带电测试方法探讨

从氧化锌避雷器(MOA)带电测试工作现场实测情况出发,分析对比目前氧化锌避雷器带电测试的方法,提出氧化锌避雷器带电测试结果综合判断的方法,以提高氧化锌避雷器运行情况分析水平。     

氧化锌避雷器电场计算分析

本文以有限元法为基础,利用ANSYS仿真软件建立了某型号252kVGIS罐式氧化锌避雷器的三维实体模型,对其电位分布和电场强度进行计算,从结果对其结构设计的合理性进行了分析。     

氧化锌避雷器在线监测研究与应用

本文对氧化锌避雷器在线监测研究与应用进行了研究，提出了目前氧化锌避雷器监视存在的问题，并提出了相应的解决措施。     

110KV氧化锌避雷器带电试验及其精度研究

本文介绍了如何在不停电的情况下对避雷器进行测试,并对带电测试过程中的干扰以及该如何抑制这些干扰进行了分析,最后给出了提高带电测试精确度的新措施。如果可以有效的提高MOA带电测试精度,那么其应用前景必将是非常广阔的,必定可以带来巨大的经济效益。     

浅析氧化锌避雷器带电测试在状态检修中的应用

随着电网的快速发展,以及用户对供电可靠性要求的逐步提高,迫切需要在充分考虑电网安全、环境、效益等多方面因素情况下,研究、探索提高设备运行可靠性和检修针对性的新的检修管理方式,状态检修是解决当前检修工作面临问题的重要手段。氧化锌避雷器在电网中起着重要的作用,它的带电测试,方法简单,数据准确,在状态检修中,发挥着重要的作用。本文主要介绍了氧化锌避雷器的带电测试原理,结合实际应用,以及它在实际应用中体现出的经济性,论证了金属氧化锌避雷器带电测试在状态检修中的重要作用。     

配网中10kV氧化锌避雷器的安装方法探讨

笔者认为避雷器的安装不能只是简单的照搬典型设计，应根据避雷器及被保护设备在系统中所起的作用来确定安装方式，下面笔者就一些较为常见的安装方式进行简单的探讨。     

研究500kV线路氧化锌避雷器的运行实践

500kV高压输出线路在实际的运行过程中,常常需要经过地质条件较复杂的地区,并且需要进行长距离的运输,在其运行的过程中,加强其防雷保护,保证其安全、稳定运行是非常必要的,本文就以某市的500kV高压输出线路为例,对氧化锌避雷器在其线路中的运行效果进行简单分析,对于线路防雷效果的提升具有积极的作用。     

钛基贱金属氧化物涂层阳极的研究进展

介绍了钛基贱金属氧化物涂层阳极的发展概状。论述了贱金属氧化物涂层阳极技术发展的必然和要解决的关键问题。重点阐述了几种有代表性、具有广阔应用前景的贱金属氧化物涂层阳极，并对其未来的发展及应用前景进行了展望．     

手持式冰点测定仪(折射率法)校准方法

简述了目前手持式折射率法冰点测定仪的用途,国内外防冻液标准现状。现有计量技术规范无法满足手持式折射率法冰点测定仪的计量校准需求,且国内暂无专门针对手持式冷却液冰点测定仪(折射率法)的计量技术规范、标准溶液的配制参考方法。介绍了手持式折射率法冰点测定仪的原理和结构,探讨了此类仪器的校准方法,讨论了主要的校准项目,同时还介绍了校准用溶液的配制方法和校准时的注意事项。     

基于卷积神经网络的超声金属材料辨识

传统的金属材料辨识方法会给被检测样品带来一定程度的损伤。文章通过采集金属材料的超声回波时域信号,采用短时傅里叶变换对其进行时频分析,得到包含金属材料微观组织信息的超声时频谱。将目标样品的超声时频谱预处理后作为训练样本,输入到构建好的卷积神经网络中进行训练。然后采集目标样品以及干扰样品的超声频谱图,分别将其输入网络进行辨识。结果表明,神经网络在训练时收敛较快,损失函数在迭代200次后收敛,在经过100次迭代后训练集准确率趋于100%。训练完成的网络模型记录着对应训练样本的特征信息,利用该训练好的网络对待测样本进行辨识,最终可实现超声金属材料辨识。     

静水压测试仪校准方法探讨

通过对适用领域、相应国家标准和技术参数的分析,介绍两种静水压测试仪的异同;同时基于以上分析,探讨静水压测试仪器校准时标准器的选择和校准方法,以及校准过程中可能遇到的问题和需要注意并采取的办法。     

Fault detection,classification, and location for active distribution network based on neural network and phase angle analysis

The improved radial basis function (RBF) method utilizes an orthogonal regression matrix to produce an artificial neural network structure based on regularized least square. The phase angle and amplitude signal of fault voltage and current are extracted based on frequency domain analysis. The proposed method adopts the fault signal for fault diagnosis synchronously. The IEEE 13-bus active distribution network (ADN) simulation model is set up in Matlab. Test results demonstrate that accuracy of the fault diagnosis can reach 98.07% and the response time of the fault classification method is less than 0.04s. The wavelet neural network (WNN) model is developed to extract the maximum decomposition level and time series behavior. The WNN method can resist noise effects and improve the fault classification accuracy by 4.3%. The effect of fault type and fault resistance on the fault location method is researched. The fault simulation result shows that the proposed method can locate a fault precisely and synchronously. The improved RBF method can diagnose the fault section, classify the fault type and locate a fault accurately in ADN. The research is significant to maintain system stability against realistic fault and network restore.     

聚合物-过渡金属氧化物纳米复合阴极材料的研究进展

聚合物－过渡金属氧化物纳米复合阴极材料在锂二次电池中是一类具有广阔应用前景的新型材料，本文综述了这类材料的制备方法和性能特征，分析了其导电机理，探讨了该研究领域的前沿问题。     

原子层淀积制备金属氧化物薄膜研究进展

原子层淀积(ALD)技术作为一种先进的薄膜制备方法近年来越来越得到重视,它能精确地控制薄膜的厚度和组分,实现原子层级的生长,生长的薄膜具有很好的均匀性和保形性,因而在微电子和光电子等领域有广泛的应用前景。本文综述了ALD技术的基本原理,及其在金属氧化物薄膜制备上的研究进展。     

Semiconductor metal oxide compounds based gas sensors: A literature review

This paper gives a statistical view about important contributions and advances on semiconductor metal oxide (SMO) compounds based gas sensors developed to detect the air pollutants such as liquefied petroleum gas (LPG), H₂S, NH₃, CO₂, acetone, ethanol, other volatile compounds and hazardous gases. Moreover, it is revealed that the alloy/composite made up of SMO gas sensors show better gas response than their counterpart single component gas sensors, i.e., they are found to enhance the 4S characteristics namely speed, sensitivity, selectivity and stability. Improvement of such types of sensors used for detection of various air pollutants, which are reported in last two decades, is highlighted herein.     

Green synthesis of metal/C and metal oxide/C films by using natural membrane as support

A protocol aiming at making use of the huge amount of naturally existing wastes such as defoliation, pericarp and egg shell for nanostructured composite materials was proposed. In this study, a green synthetic route using naturally existing membrane as support was developed for the synthesis of nanostructured and porous metalor metal oxide-carbon composite films. Different metallic ions （Co2＋, Ni2＋, Fe3＋, Mn2＋ or Cu2＋） can be easily adsorbed onto egg membranes and the followed calcination process results in the formation of Co/C, Ni/C, Fe304/C, MnO/C or CulCu2OICuOIC composite films. The electrochemical studies demonstrate that such composite films would have potential applications in energy fields. This method would provide a general green concept for chemical synthesis and be beneficial to the global sustainable future.     

Formation of chromium rich oxide scales for protection against metal dusting

Abstract

Metal dusting is a disintegration of metals and alloys into graphite and metal particles, caused by strongly carburizing gas mixtures mainly in the temperature range 400–700°C. Protection of steels against metal dusting is possible through the formation of dense chromium rich oxide scales but it is not guaranteed that such scales are formed at low temperatures, even on high Cr-steels.

Surface analytical studies have been conducted on the formation and composition of the oxide scales on 9–20%Cr steels. The growth of oxide films was followed by AES for 3 hours at 10^–7 mbar O₂ great differences were observed in dependence on surface finish. On ground samples, Mn and Si appeared early and Cr-rich oxide was formed, whereas on chemically etched samples Fe-rich oxides grew.

After long term exposures (240 h) under metal dusting conditions, i.e. in CO–H₂–H₂O mixtures at 600°C, thin Cr-rich scales were observed on ground steels which were impermeable to carbon whereas on chemically etched steels thick Fe-rich scales had grown and carbon penetration was detectable. Accordingly, the oxide formation on Cr-steels at relatively low temperatures strongly depends on the surface treatment. Any surface working such as grinding and sand-blasting etc. introduces dislocations and causes a fine-grained microstructure near the surface, and the dislocations and grain boundaries act as rapid diffusion paths for supply of Cr to the surface in the first minutes of exposure, which leads to the formation of a protective oxide scale.